IEEE C57.12.34-2009 pdf download Errata to IEEE Standard Requirements for Pad-Mounted, Compartmental-Type, Self-Cooled, Three-Phase Distribution Transformers (2500 kVA and Smaller)- High-Voltage: 34 500 GrdY/19 920 Volts and Below; Low Voltage: 480 Volts and Below
7.2 Tolerance on impedance voltage
The tolerance on nominal impedance voltages shall be as specified in 9.2 ofIEEE Std C57.12.00.
7.3 Tolerance on impedance voltage on a tap
The percent departure of the tested impedance voltage on any tap from the tested impedance voltage atrated voltage shall not be greater than the total tap voltage range and shall be expressed as a percentage ofthe rated voltage.
8. Tests
8.1 General
Except as specified in 8.2 of this standard, tests shall be performed as specified in IEEE Std C57,12.00 andIEEE Std C57.12.90.
8.2 Dielectric tests
For wye-wye connected transformers, no applied voltage test is required on the high-voltage winding. Aninduced voltage test shall be performed as specified in IEEE Std C57.12.90. The voltage induced betweenthe high-voltage line terminals and ground shall be the lower of the following values:
a) 3.46 times the rated high-voltage winding voltage plus 1000 volts, or
b) The applied voltage test values provided in IEEE Std C57.12.00, Table 5.
9. Construction
9.1 General
A pad-mounted, compartmental-type transformer shall consist of a tank with high-voltage and low-voltagecable terminating compartments, as shown in Figures 3 and 6 or Figures 8 and 10 of this standard, Thecompartment shall be separated by a barrier of metal or other rigid material.
9.2 Compartment configuration
The high-voltage and low-voltage compartments shall be located side-by-side on one side of thetransformer tank When viewed from the front, the low-voltage compartment shall be on the right.
9.3 Access
Each compartment shall have a door so constructed as to provide access to the high-voltage compartmentonly after the door to the low-voltage compartment has been opened.There shall be one or more additionalcaptive fastening devices that must be disengaged before the high-voltage door can be opened. Where thelow-voltage compartment door is of a flat panel design, the door shall have three-point latching with ahandle provided for a locking device. The compartment doors shall be of sufficient size to provide adequateoperating and working space when removed or open, The doors shall either be equipped for latching in theopen position or designed for manual removal.